GEOLOGY OF THE

RAVEN RUN NATURE SANCTUARY

completed March, 1985

@over Picture; The stone foundation of Evans' m i 11.

GEOLOGY OF RAVEN RUN NATURE SANCTUARY

Introduction to the trail quide

Geology is the science of Lhe earth and L11o~:o w h o study geology are called geologists. Part of a geologist's job is to determine how the rocks we see today in quarrys, r-oadcuts, parks, and other areas, were ori y inall y formed.

Haven Run Nature Sanctuary is located on Lhe eastern edge of the Bluegrass region in cent;ral Kentucky. This region is a broad, oval platform that geologists call the Jessamine Dome. The Jessamine Ilorne is part of an even larger feature called the CincinnaLi Arch. Figure 1 shows how millions of years ago the sediments in central Kentucky were raised relative Lo I eastern and western Kentucky. The area that was relative1 y uplifted is called an arch. The areas ttml;

P E N N . 1. p l a n .

O R D . L A T E P A L E O Z O I C 2 2 0 n l l l l o n vm.18 a g o

4 ARCH

E N D O F P A L E O Z O I C 1 0 0 m l l l l o n v.818 a g o

REGIONAL EVOLUTION of the C INCINNATI ARCH

C E N T l A L I l N T U C I Y

were r e l a t i v c ? l y downdropped on e i t h e r s i d e o f t h e arcti a r e c a l l e d b a s i n s . A f t e r t h e a r c h was formed e r o s i o n re- moved g r e a t q u a n t i t i e s o f r o c k s and s e d i m e n t s form t h e a rch . T h i s l e f t o l d e r r o c k s e x p o s e d o n t o p t h e a r c h and younger r o c k s exposed i n t h e b a s i n s . S i n c e Raven Run is l o c a t e d n e a r t h e t o p o f t h e a r c h , some o f t h e o l d e s t ex - posed r-ocks i ri t h e s t a t e a r e found h e r e .

Most of !;he r o c k s you c a n see i n t h e p a r k a r e ca l l - ed c a r b o n a b e s . ' rhese t y p e s o f l a c k s a r e p r e d o m i n a n t l y rnatle-up of t h e m i n e r a l c a l c i t e . C a r b o n a t e s are formed i r l warm, s h a l l o w s e a s , o f t e n o r i n p a r t f rom t h e r e m a i n s of s m a l l sea c r e a t u r e s . When t h e s e r e m a i n s are p r e s e r v e d Lhey a r e c a l l e d f o s s i l s .

F i g u r e 2 shows how g e o l o g i s t s s u b d i v i d e t h e c a r b o - nat,e r o c k s i n t h e p a r k . The lower and t h e r e f o r e o l d e r c a r b o n a t e s a r e c a l l e d t h e High B r i d g e Group. The g r o u p is d i v i d e d i n t o t h r e e f o r m a t i o n s . F o r m a t i o n s are u s e d t o c l a s s i f y r o c k s t h a t are s i m i l a r a n d c a n b e mapped o v e r l a r g e a r e a s . A t Raven Run, t h e High B r i d g e Group c o n s i s t s o f L t i e Carnp Nelsorl L i m e s t o n Format i o n , t h e Oregon Forma- t i o n and t h e Tyrone L imes tone F o r m a t i o n . The u p p e r and t h e r e f o r e younger c a r b o n a t e s a r e p a r t o f t h e L e x i n g t o n 1,imest;one Format i o n . The L,exington L imes tone F o r m a t i o n can h e f u r t h e r s u b d i v i d e d i n t o s p e c i f i c members. Members are s i n ~ p l y a more d e t a i l e d c 1 a s s i f i c a l ; i o n . T h r e e o f t h e lower members o f t h e L e x i n g t o n 1 , imestone a r e p r e s e n t i n Ltlc park. 'T'hese a r e L t i e C u r d s v i l l e Member, t h e G r i e r M e m - b e r and t h e Tanglewood Member. The members o f t h e Lex- irlg t o r i I , i n ~ e s t o n e Format i on a r e g e n e r a l 1 y b u r i e d b e n e a t h t h e s o i l on t h e upper. s l o p e s a n d ' r i d g e t o p s o f t h e p a r k . liowevor., t h e fo rmat , ions o f t h e High B r i d g e Group are s ~ ) e c t , a c u l a r l y e x p o s e d i n t h e gorges and a l o n g t h e t r a i l s o f Raven Run..

'I'he c a r b o n a t e r o c k s t h a t make up t h e s e f o r m a t i o n s were fornted i n a s h a l l o w s e a t h a t c o v e r e d much o f t h e c?asLerri [Jriited S t a t e s o v e r 460 m i l l i o n y e a r s ago . T h i s Lime was p a r t o f what g e o l o g i s L s c a l l t h e O r d o v i c i a n p e r i o d . I luri ng t h e O r d o v i c i a n p e r i o d t h e Raven .Run a r e a p r o b a b l y looked 1 i k e t h e t i d a l f l a t s and s h a l l o w seas o f t h e Bahama Tsl a n d s t o d a y . However, many o f t h e c r e a t u r e s that, l i v e d i n t h i s O r d o v i c i a n s e a were v e r y d i f f e r e n t

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1 rora \ ,he c r e a t u r e s w e see t o d a y . F i g u r e 3 is a i l l u s t r a - Lion o f what t h e O r d o v i c i a n seas o f t h e Raven Run a r e a might h a v e looked l i k e 460 m i l l i o n y e a r s a g o . I n t h o s e s e a s w e r e s q u i d - l i k e c r e a t u r e s w i t h s h e l l s c a l l e d ceph- a l o p o d s , s t r a n g e c o u s i n s o f t h e h o r s e s h o e c r a b c a l l e d t,ri l o b i tes, c r e a t u r e s t h a t r e s e m b l e d u n d e r w a t e r f l o w e r s c a l l e d c r i n o i d s , p r i n ~ i t i v e s n a i ls c a l l e d g a s t r o p o d s , p r im- i t i v e c l a m - l i k e o r g a n i s m s c a l l e d b r a c h i o p o d s , small c o r a l - 1 i k e creat:t~res c a l l e d b r y o z o a n s , a s w e l l as many rela- L i v e s o f t h e modern c o r a l s and m a r i n e worms.

F'icjure 4 is a g e o l o g i c a l map o f t h e p a r k . I t js on pnye 6 of' I ,h is p a m p l ~ l e t . G e o l o g i c a l maps are u s e d t o show the: r o c k f o r m a t i o n s o c c u r i n g a t t h e e a r t h ' s s u r f a c e . When you s t a r t o u t a t t h e b a r n , t h e map i n d i c a t e s t h a t I.l~e r o c k s r i g h t be low y o u r f e e t are p a r t o f t h e Lex ing- Lon Limes tone F o r m a t i o n . When you g e t down t o t h e water- f a l l s a t s t o p 4 t h e map i n d i c a t e s t h a t you are s t a n d i n g or1 r o c k s which are p a r t o f t h e Camp Nelson F o r m a t i o n .

- 'I'hjs p a m p h l e t is a t r a i l g u i d e t o t h e Raven Run

Not,ur.e S a n c t u a r y . P o i n t s ol- geological i n t e r e s t a l o n g Lhe Red T r a i l a r e marked on t h e map ( p a g e 6 ) . B r i e f d e s - c r i p t i o n s o f t h e p o i n t s a r e l i s t e d i n t h e f o l l o w i n g p a g e s 6 1 s g e o l o g i c a l s t o p s . 'These s t o p s c a n b e s e e n f rom t h e d e s i y n a t e d t r a i 1 s as shown on t h e map. Walking o f f t h e L r a i l c a n b e v e r y d a n g e r o u s and is d i s c o u r a g e d . P l e a s e d o n o t remove o r v a n d a l i z e t h e r o c k s o r f o s s i l s i n t h e park. 'This p a r k is meant t o b e e n j o y e d by e v e r y o n e . Leave on1 y f o o t p r i n t s , t a k e o n l y memories .

LIFE IN THE O R D O V I C I A N S E A S

4 60,000,000 y e a r s a g o

f i g . 3 1

1 ) h o r n c o r m 1 3 ) b r a c h l o ~ o d s 5 ) a l o e . 7 ) m a r l n e w o r m 8 ) l r l l o b l t a

2 ) c o l o n l a l c o r a l 4 ) c r l n o l d s 6 ) c a ~ h a l o ~ o d 8 ) 0 a ~ l r o ~ o d 1 0 ) b r y o r o a n

GEOLOGIC MAP of the RAVEN RUN NATURE SANCTUARY CncLTinuM TO?^

f l g . 4 af ter Black (1967)

STOP 1

A s you came down t h e h i l l s i d e on t h e ~ e d T r a i l you were w a l k i n g o v e r t h e L e x i n g t o n L i m e s t o n e F o r m a t i o n . T h e s e r o c k s are c a l l e d l i m e s t o n e s , b e c a u s e t h e y . a r e pr-e-- d o m i n a n t l y made u p o f c a l c i u m c a r b o n a t e or "lime". F i g u r e 5 is a s k e t c h o f t h e c r e e k a t s k o p I.;.When you l o o k i n t o Lhe c r e e k bed. you c a n s e e f ' t k a t . t h e r e are many p a r a l l e l c r a c k s i n t h e l i m e s t o n e . . G e o ~ o g i s t s c a l l t h e s e s t r a i g h t c r a c k s i n t h e r o c ~ ~ ; , ~ : j o . i . r i t s ~ A t t h i s SLOP t h e j o i . n t s are a l l a l l i g n e d . i n . t h e . . .. sarne d i r e c t i o n . A t o t h e r . p o i n t s a l o n g t h e t,F+"iii..yow'may see a n a d d i t i o n a l set of j o i n t s alligned:.approx-iinately 80" f rom t h i s set . J o i r ~ t s c a n make t h e r o c k v e r y weak, s o t h a t i t i s e a s i l y b r o k e n a p a r t . A s yoi1.walk a l o n g t h e c r e e k you c a n see how w a t e r f a l l s have formed where r o c k s h a v e b r o k e n a.Long t h e :joir~l:s:

JOINTS

BLOCK DIAGRAM of the RAVEN RUN AREA

V I E W

F R O M A C R O S S

T H E R I V E R

( e h r t )

-- -- - - -

A) . Park entrance

8). Barn and parklno

C ) . South Fork Raven Run Ck .

0 ) . Mlddle Fork Raven Run Ck.

El . Nor th Fork Raven Run Ck.

F). Rlver overlook

(3). Chandler Ck.

'The secont l s t o p is l o c a t e d 200 f e e t p a s t t h e t r a i 1 j u r l c t i o n . I f you l o o k t o y o u r r i g h t a b o u t 20 f e e t u p f rom Lhe t r a i l you c a n see a p r o t u d i n g l e d g e o f r o c k . The l e d g e is made up o f l i m e s t o n e f rom t h e C u r d s v i l l e Member o f t h e Lex ing Lor) Leimestone F o r m a t i o n . The 1 i m e s t o n e be - n e a t h t h e l e d g e is f rom t h e T y r o n e 1 , imes tone F o r m a t i o n . When two f o r m a t i o n s meet l i k e t h i s , i t i s c a l l e d a s t ra - t i g r a p h i c c o n t a c t .

Note t h e d i f f e r e n c e s be tween t h e t w o t y p e s o f l i m e - s t o n e . 'I'he C u r - d s v i l l e L i m e s t o n e i s v e r y r o u g h t o t h e t o u c h ;iri$ c o n t a i n s many f o s s i l s . The f o s s i l s are more e a s i l y s e e n o n z t h e u n d e r s i d e o f t h e l e d g e . On t h e o t h e r hand, t h e T y r o n e h L i m e s t o n e is much snroother t o t h e t o u c h , and (:on t s i r i s much fefnler f o s s i 1 s.

* '-

COMMON F O S S I L S

horn cora ls cr inoids bryo r o a n s bur rows

F i g u r e 6 shows sonre o f t h e f o s s i l s you c a n see i n t h e l e d g e r o c k . T h e s e f o s s i l s a r e t h e r e m a i n s o f c r e a t u r e s t h a t l i v e d h e r e o v e r 460 m i l l i o n y e a r s a g o . F i g u r e 6 a l s o shows t h e c u r i o u s s t r a i g h t l i n e s t h a t you c a n see i n t h e Tyrone L imes tone , b e n e a t h t h e l e d g e . They r e p r e s e n t a d i f f e r e n t k i n d o f f o s s i l . Whi le t h e f o s s i l s i n t h e l e d g e r e p r e s e n t t h e a c t u a l r e m a i n s of a n o r g a n i s m , t h e s e 1 i n e s l.epr.esen t t h e t r a c k s or -gani sms l e a v e b e h i n d . They w e r e orlc:e t h e b u r r o w s cjf s m a l l w o r m s a n d c l a m s . When b u r r o w s a r e s t r a i g h t - u p 1 i k e t h e s e , g e o l o g i s t s c a l l them ' v e r t i - c a l b u r ~ . o w s ' . They a r e e v i d e n c e t h a t c r e a t u r e s were l i v i n g i n t h e mud on t h e a n c i e n t t i d a l f l a t s . A p p a r e n t l y when t h e t i d e s came i r i , t h e c r e a t u r e s came o u t o f t h e i r t )urrows t o f e e d . Then when t h e t i d e s wi thdrew, Lhey re- t , r -eated back i n t o t h e i r moisL b u r r o w s s o t h a t t h e y would n o t d r y -01~1, i n t h e hot; s u n .

STOP 3

Water s e e p s o u t o f t h e l i m e s t o n e r o c k s a t sevr -a1 p l a c e s t h r o u g h o u t t h e p a r k . When t h e s e s e e p s a r e l a r g e enough t h e y are c a l l e d n a t u r a l s p r i n g s . F i g u r e 7 stlows how a s p r i n g may form. Ra in f a l l i n g on t h e e a r t h ' s s u r - f a c e s e e p s i n t o t h e g round . A s t h e ' g r o u n d w a t e r ' t r a v c l s t h r o u g h t h e s o i l i t becomes m i l d l y a c i d i c . CarbonaLe r o c k s , s u c h a s l i m e s t o n e c a n b e d i s s o l v e d u n d e r g r o u n d by t h e s e a c i d i c w a t e r s . O f t e n t h e g r o u n d w a t e r works i t ' s way down j o i n t s l i k e you s a w a t s t o p 1. A s t h e a c i d i c water moves u n d e r g r o u n d i t en1 a r g e s t h e j o i n t s , for-mi ng s o l u t i o n a l c a v i t i e s . Over a l o n g p e r i o d o f t i m e , l a r g c amounts o f t h e l i m e s t o n e may b e d i s s o l v e d away, f'orminy a c a v e . Anothe r f e a t u r e t h a t may form i n t h i s s i t u a t i o n a r e bowl-shaped d e p r e s s i o n s c a l l e d s i n k h o l e s . A l l o f t h e s e f e a t u r e s ; t h e s e e p s , s p r i n g s , s i n k h o l e s , s o l u t i o n c a v i t i e s , and c a v e s a r e c a l l e d ' k a r s t ' by g e o l o g i s t s . They a r e common t h r o u g h o u t Ken Lucky. In f a c t , Kentucky is o n e o f t h e most famous k a r s t areas i n t h e w o r l d .

C R E E K u

r o c k d e b r l a

S E E P

NATURAL

KARST FEATURES

T h e r e a r e many t h i n g s t o see i n t h i s a r e a . The r o c k s a t t h e w a t e r f a l l s are p a r t o f t h e Camp N e l s o n Ii'ocn~atiort. ' I 'h is is t h e o l d e s t f o r m a t i o r > i n t h e p a r k . I t is a l s o t h e o l d e s t e x p o s e d f o r m a t i o r l i n Kentucky.

if you l o o k a t t h e r o c k s a r o u n d t h e f a l l s or t h e l a r g e b o u l d e r n e a r t h e o l d mi l 1 you c a n see a l l sorts o f t w i s t - i n q f e n t , l ~ r e s Chat st;and out; o n t h e i r s u r f a c e s . (:eologi sts b e l i e v e t,ttese are anot;her k i n d o f f o s s i 1 b u r - r o w . il'i qt1r.c H shows t h e d i f f ' e r e n c e be tween t h e s e b u r r o w s and t h e bur rows t h a t c a n b e s e e n i n t h e T y r o n e F o r m a t i o n . 'I'hese f o s s i 1 t r a c k s were formed by worm-1 i k e o r g a n i s m s niovirrg o v e r o r t h r o u g h ttre muds. They a r e known a s h o r i - zorrl;nl o r l a t e r a l bu r rows .

T R A C E F O S S I L S

t h e n now

v e r t l c a l bur rows

then \) - .

now

('l'yt-one F'm. ) l a t e r a l b u r r o w s

(Camp Ne l son Fni. ) S1'0I' 5

A t r a i l l o a d s u p t h e c r e e k t o a v e r y l a r g e w a t e r f a l l . I t i s much s a f e r t o s t a y a l o n g t h e c r e e k and n o t c l i m b t h e h i l l s i d e . F i g u r e 9 g i v e s some i d e a how t h e w a t e r f a l l was f o r n ~ e d . The t o p o f t h e w a t e r f a l l is a s t r a t i g r a p h i c conLacL be tween r o c k s of t h e T y r o n e a n d Oregon F o r m a t i o n s . , J o i n t s , l i k e t h o s e you saw a t s t o p 1, c r e a t e d l i n e s o f weakness i n t h e r o c k s . S i n c e , a t t h i s l o c a t i o n , t h e O r e - gon r o c k s w e r e weaker t h a n t i r e o v e r l y i n g T y r o n e r o c k s , t h e l'yr-one w a s l e f t a s a r e s i s t a n t l e d g e f o r t h e water to f a 1 l o v e r . Bu t e v e n t h e T y r o n e x-ocks are g r a d u n l 1 y

W a l e r b e g l n s l o

e r o d e a l o n g l o l n l

n e s l s l a n t r o c k

I o r m o a l e d g e

on r e s l s t a n l r o c k s

a r e e r o d e d

s e s l r t s n l

Through Ilme the fal ls

r.etreal up the valley

E r o d e d m a l e r l a l I s

washed downstream

e r o d e d . Through time t h e w a t e r h a s e r o d e d t h e canyon f u r t h e r b a c k i n t o t h e h i l l s i d e , to t h e p o i n t where you see i t t o d a y . Someday, thousa t lds o f y e a r s f rom now, t h e f a l l s w i l l re t reat e v e n f u r t h e r up t h e v a l l e y .

STOP 6

I f you l o o k a t t h e map you c a n n o t i c e t h a t t h e t r a i l w inds a r o u n d a s m a l l v a l l e y t h a t b r -eaks away f r o m t h e main g o r g e . T h i s v a l l e y fo l . lows a l a r g e b r e a k i n I ,hc : s u r f a c e o f t h e e a r t h , known as a f a u l t . F a u l t s d i f f e r - from j o i n t s b e c a u s e r o c k s a l o n g a f a u l t move. T h i s t y p e o f ~rtovement is wha t c a u s e s a n e a r t h q u a k e . D o n ' t wor ry t h e f a u l t you are w a l k i n g a l o n g h a s n o t moved f o r m i l l - i o n s o f y e a r s . B e c a u s e o f a l l t h e v e g e t a t i o n and soil c o v e r , t h e f a u l t is d i f f i c u l t to see. However, many f a u l t s c a n b e s e e n i n t h e r o a d c u t s i n t h e Raven Run area. A f t e r l e a v i n g t h e p a r k i f you d r i v e o v e r t h e Kentucky R i v e r by C l a y s F e r r y o n Old Richmond Road ( R o u t e 2 5 ) , o r a t t h e b r i d g e n e a r Camp Ne l son , on N i c h o l a s v i l l e Road I ( R o u t e 27) you c a n see good e x a m p l e s o f f a u l t s i n t h e

I

r o a d c u t s . 1 i I I

The rock at the top of the overlook belongs to the Camp Nelson Formation. This is Lhe same formation you saw back at stop 4. Notice that you can still see the trace fossils in the limestone rocks at your feet. Figure 10 shows a pitcur-e of these burrows and the other comnron Fossils at the overlook.

COMMON FOSSILS a t . t h e o v e r l o o k

.'-' . .. . .. ...

( 3 a s t r o p o d a f a n o l e n i ~ n a i t a ) C e p h a l o p o d s T r a c e F o s s l t S

f a n o t a n t oqold . ) t a n a i . o I I r a a L a

f i g . 1 0 a n d b r r r o r l )

W r t l k out to khe over-look. The center of this pam- phlet has a block diagram thaL shows Raven Run park as it would be seen from across the river. It also shows t-he rock units that are found in the park.

In many areas of the Bluegrass, the Kentucky River winds through a gentle valley. But here the river has been forced to cut through the resistant carbonates of (,he iiigtj Bridge Group. Because they are hard to erode Ltte Kentucky River has had to cut a steep-sided gorge into the rocks, known as the Palisades.

Sometimes if you look at the river right below the look-out; you can see a sand bar. Sand bars commonly form in river bends and at locations where another creek or river join. This sand bar is a result of sediment that has been washed out of the Raven Run gorge. Utimately t,hese sediments, which have been formed by erosion of the rocks in the area, may end up in the Ohio River. From there it may be washed into the Nississjppi River and as far as the Gulf of Mexico, over 1500 miles away!

STOP 8

A s you h e a d u p t h e h i l l f rom t h e o v e r l o o k you w i l l walk t h r o u g h a moss -covered p a s s . When t h e t r a i l l e v e l s o u t o n t h e o t h e r s i d e o f t h e p a s s , you are b a c k i n t o t h e Tyrone F o r m a t i o n . The Tyrone F'ormat;iot~ is easi 1 y r e c o g - n i z e d b e c a u s e o f i t ' s w h i t e c o l o r . Most o f t h e o t h e r for- m a t i o n s i n t h e p a r k are d a r k g r e y , t a n o r b u f f c:olor.

Look For t h e c i r c u l a r mound s h a p e s i n t h e l i g h t c o l o r e d r o c k s a l o n g t h i s par t o f t h e t r a i l . T h e s e a r e y e t a n o t h e r k i n d o f f o s s i l . F i g u r e 11 shows a s k e t c h of t h e s e mounds. They r e p r e s e n t t h e r e m a i n s o f a c o l o n i a l coral c a l l e d T e t r a d i u m . T h e s e c o r a l s f l o u r i s h e d i n p a r t s o f t h e a n c i e n t t i d a l f l a t , when t h e Tyrone F o r m a t i o n was d e p o s i Led.

You c a n a l s o see pat,tctr-ns o f c r a c k s i n L t l e 1 imestonr:. These are c a l l e d mudcracks . A s k e t c h o f t h e s e js a l s o shown i n f i g u r e 11. The mudcracks were formed j u s t a s t h e y are t o d a y . I n some a r e a s when t h e t i d e w i t h d r e w , t,he b e a c h a r e a w a s l e f t t o d r y i n t h e s u n a n d t h e muds c r a c k - ed .

COLONIAL CORAL F O S S I L . .

STOP 9

The 1.1lins o f t h e s t r u c t u r e i n f r - o n t of you is a l i n t e s t o n e k i l n . A k i l n is l i k e a l a r g e f u r n a c e . Y e a r s a g o t h e s e t t l e r s i r l t h i s a r e a baked t h e l i m e s t o n e , r o c k s i n t h i s k i l n to p r o d u c e ' l i m e ' . The l i m e was u s e d i n making mortar a n d plaster f o r c o n s t r u c t i o n pur -poses . T h e s e t y p e s o f k i l n s a r e no l o n g e r i m p o r t a n t s i n c e

I i t h e r e a r e now more modern nrethotls f o r o b t a i r l i n y 1 i rne .

l'he last part of the trail follows the old stone fence. Early settlers commonly used the carbonate rocks of the area for- building. They made good building nlater- ial hecause they broke along joints and bedding planes into block-like shapes. They also ware abundanl; and e a s i l y accessibie. The kiln at stop 9 was made out of 1 inrestone from the Lexington L,i mestone Formation. 'The

nt i l 1 at stop 4 was made out of d~lomitic liniestone from Ltte Oregon Formation. In fact, even many of the more ~rrotfer-n buildings in the towns around the park were made L't.orn t;he carboriate r.ocks Like yo11 saw in the park today. .

'i'his trail quide. was meant to give the visitor to Haven Run a brief introduction t,o the geology of the ULnegr.ass area. If you are interested in learning more about the geology of Kent.ucky many local libraries will be ab le to help you. Information may also be obtained f rorn the state ilniversi t ies and the Kentucky Geological s1;tl'vey.

The +olPowing references discuss i n more d e t a i l t he geology o f the Raven Run area.

Black, D. F. B. , Cressman, E. R. , and MacQuown, W. C. Jr. , ( 1965) , "The Lexington Limestone (Middle Ordovician) O F Central Kentucky"; U.S. Geol. Surv., H u l l e t i n 1224-C, Z9pp.

Black, D.F.B., 1967, "Geologic map o f the Coletown Quadrangle, east-central Kentucky"; U.S. Geol. Surv. , 6Q-644.

Cressman, E.R., and Noger, M.C., 1976, "Tidal- f l a t environments i n the High Bridge Group (Middle Ordovician) o f Central Kentucky"; U.S. Geol. Surv., Series 10, Report o f Invest iga t ions 16, 15pp.

Cressman, E.R., 1973, "L i thos t ra t ig raphy and depositionak environments o f tho Lexington Limestone (Ordovician) o f cent ra l Kentucky; U.S. Geol. Surv., Prof+essionaI Paper 768, bipp.

MrFarlan, Arthur C., 1943, l+ology o f Kentucky; Un ivers i ty o f Kentucky, Lexington, KY, 531pp.

Topographic Map of the Raven Run Nature Sanctuary, Fayet te County, Kentucky; scale 1"=400'.